Zheng H Z, Cai B, Feng Y H, Sun H, Cai K R
Department of Physiology, Guangdong Medical College, Zhanjiang 524023.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2000 Nov;16(4):314-7.
To Investigate the myocardial ultrastructure effects of SMT on the ischemia reperfusion injury (IRI) in the rat heart.
Eighteen Spraqua-Dawley rats were randomly divided into three groups: ischemia reperfusion group (IR), subjected to 60 min of o-cclusion and 20 min of reperfusion of the anterior descending branch of left coronary artery; IR + SMT group (SMT), given the selective iNOS inhibitor S-methylisothiourea sulfate (SMT, 5 mg/kg, i.v.) before reperfusion; control group (C), didn't occlude coronary artery after exposing heart and observed 80 min. Electrocardiogram (ECG) was recorded. Nitrite and nitrate content were measured in myocardium and blood serum. The changes of myocardial ultrastructure were observed with electron microscope.
Ischemia reperfusion induced ST segment elevation and T waves inversion or tallness in ECG, damaged myocardial ultrastructure, increased nitrite and nitrate content in myocardium and blood serum after IR compared with before IR(P < 0.01). Administration of SMT improved the changes of ECG and the injury of myocardial ultrastructure. Nitrite and nitrate content of myocardium were lower than IR group (P < 0.05). The change of nitrite and nitrate level of blood serum in SMT group was nearly in C group.
SMT can prevent myocardium injury from reperfusion following ischemia.
研究S - 甲基异硫脲（SMT）对大鼠心脏缺血再灌注损伤（IRI）心肌超微结构的影响。
将18只Sprague - Dawley大鼠随机分为三组：缺血再灌注组（IR），左冠状动脉前降支闭塞60分钟，再灌注20分钟；IR + SMT组（SMT），再灌注前给予选择性诱导型一氧化氮合酶抑制剂硫酸S - 甲基异硫脲（SMT，5 mg/kg，静脉注射）；对照组（C），暴露心脏后不闭塞冠状动脉，观察80分钟。记录心电图（ECG）。测定心肌和血清中的亚硝酸盐和硝酸盐含量。用电子显微镜观察心肌超微结构的变化。
缺血再灌注导致心电图ST段抬高，T波倒置或高耸，损伤心肌超微结构，与缺血再灌注前相比，缺血再灌注后心肌和血清中的亚硝酸盐和硝酸盐含量增加（P < 0.01）。给予SMT改善了心电图变化和心肌超微结构损伤。心肌中的亚硝酸盐和硝酸盐含量低于IR组（P < 0.05）。SMT组血清中亚硝酸盐和硝酸盐水平的变化与C组相近。
SMT可预防缺血后再灌注引起的心肌损伤。
